Refrigerating apparatus



Jan. 16, 1940. J. KARMAZIN 2,187,035

I REFRIGERATING APPARATUS I Filed Dec. 18, 1937 2 Sheets-Sheet 1 Jan. 16, 1940, J. KARMAZIN 2,187,035

REFRIGERATING APPARATUS Filed Dec. 18, 1937 2 Sheets-Sheet 2 45' &

INVENTOR. JG/m MeMAz M 10: ATTORNEYS.

Patented Jan. 16, 1940 r UNITED STATES PATENT OFFICE REFRIGERATING APPARATUS John Karmazin, Grosse Ile, Mich assignor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application December 18, 1937', Serial No. 180,630

. v 4 Claims. (Cl. 62 -126) This invention relates to coolingelements for Fig. 6 is a horizontal sectional view through refrigerating systems. one of the sections of the cooling element shown An object ofm-y invention is to provide an imn ga proved cooling, element .of pressed sheet'metal F g. 7 is a fragmentary sectional view similar v t t g y. l to Fig. 6 showing a liquidrefrigerantdistributing 5 Another object iqmy:inventiomis to unidirecpipe in elevation within the refrigerant passage tionallynest a plurality of: :similarepressedv'sheet of a modified cooling element section;

5 constructi'on.

metal members together and;to bond; the mem- Fig. 8 is a fragmentary sectional view taken on bers ,to one another to provide a .unit having a the line 88 of Fig. 6; and I 1o finned closed refrigerant passage therein and to Fig. 9 is an enlarged end view of a header struc- 1o assemble a pluralit-y of such units together to ture located on the end of each section of the form a unitary cooling element of any predeunit of the unitary cooling element. termined size containing a plurality of banks or Referring to the drawings, for purposes of ilrows of such units. lustrating my invention, I have shown in Fig. 1 16. A further object of my invention is to provide thereof a cooling element, generally represented a cooling ele'ment of pressed sheet metal conby the reference character If], such as an evapstruction. having a plurality of refrigerant pasorator of a refrigerating system. .The cooling sages. therein and means for circulating liquid element or evaporator I0 is of a unitary conrefrig'erant to and gaseous refrigerant from the struction and comprises a plurality of sections plurality of passages in parallel, which means or units ll, each of which includes a plurality 20 provides for the exchange of heat between liquid of pressed sheet metal members to be hereinafter refrigerant entering each of the passages and described. The sections have a closed refriggaseous refrigerant. flowing therefrom. erant passage formed therein, andeach passage In making a cooling element having the feais provided with a refrigerant inlet connection tures of the preceding objects embodied therein, l2 and a refrigerant outlet connection H. The 25 itis a stil u t er d more p fi je t 0 connections l2 are connected in parallel with one the inventionto provide the element with means another to the sections II and communicate, which, in addition to distributing the 13112000186 through pipes IS, with 3, liquid refrigerant coninc min l q re rant to a plurality of veying pipe ii of a closed refrigerating system p int along h l h f th fri erant p s- (not shown). The connections H are likewise 3o sages thereof, also stiffen d increases h connected in parallel with one another to the structural s th O 't e e e e tsections II and communicate, through pipes l1, Further objects and advantages of the present with a, gaseous refrigerant .retum pipe IQ of the invention Will be pp e t from e follow n refrigerating system. The horizontally aligned des p reference be g had to the accomrows of sections or units ll of the element I0 o pany ne draw n w n a pr f rr d formf are secured together by bolts or thelike l9.passthe present invention is clearly shown. ing through holes 2| (see Fig 2) provided in In the drawin s outwardly flanged portions 22 of relatively heavy Fig. 1 is an end view of a sectional unitary end plates 23. The plurality of superimposed 40 cooling element of a refrigerating system conhorizontally disposed rows of sections or units ll 0 s ru in accordance w h my inven ion; of element In are secured together by the bolts Fig. 2 is an enlarged horizontal sectional view 9 extending through the flanges 22 and throu h through one of the sections of the cooling elea pair of brackets 24 utilized to mount the coolment shown in Fig. 1 and disclosing a refrigerant m element i a, compartment to be-cooled. Each passage provided therein; section II of element. In is provided with a drip 45 Fig. 3 is'a vertical sectional view taken on the t generally represented by the reference line 3- of Fi 2 h w a liquid refrigerant character 26, and the troughs 26 serve to convey distributing tube within the refrigerant passage; moisture dripping from the units II to one end Fig. 4 is a sectional view taken on the line of the cooling element from where the water is 4-4 of Fig. 2 showing a heat exchanger incorconducted to a drain. v r .r t

porated in the end of a section of the cooling By referring now to Fig. 2 of the drawings, it element; g v will be noted that each unit or section H of the Fig. 5 is an end view of a unitary cooling elecooling element Ill comprises a plurality of sheet ment comprising refrigerant evaporatingsections metal members 8|. Each member 3] includes a of modified form; fin portion 32 and a pressed cup-like tube portion 33. The cup or tube portion 33 or each member 3| is tapered and the members 3| are stacked one upon another with the cup portions 33 thereof telescoped together to provide walls of a closed refrigerant evaporating passage 34 in the section II. tion 33 of each member 3| has ear-likes portions 36 punched therefrom to provide openings 31 and 33 (see Fig. 3) for the flow of refrigerant throughout the length of passage 34. The web portion 33, left in wall 35 of members 3| by the punching of ears 36 therefrom, has a small rectangular hole punched therefrom which receives a tube or pipe 4|. Tube or pipe 4| is rectangular in cross-section and has its one end plugged as at 42 and has its other end rounded as at 43. Tube or pipe 4| is also provided with a long narrow slot 44 in its upper surface and the open communication of tube 4| with passage 34, between the cars 36, provides a plurality of outlets along the length of passage 34 for incoming liquid refrigerant. At one end of section or unit H a punched cup 46 is placed over the refrigerant passage forming cup portion 33 of the last member 3| to close that end of passage 34. A relatively heavy end plate 41, having a hole 43 provided therein, is positioned over the cup 46. At the other end of section or' unit II a punched member 5|, having an open inner end 52 and a flanged open outer end 53, is fitted into the end member 3|. A flanged opening 54 on the relatively heavy end plate 23 is placed over the punched member 5| and is provided with a circular shoulder 55 of larger diameter than the flanged portion 54 thereof. A pipe or conduit 53 having a plurality of fins 51 secured thereto and extending therearound has its one end 53 fitted over the rounded end 43 of pipe 4|. The other end 53 of finned pipe or conduit 53 is secured in a hollow plug-like connecting member 3| carried by header 32. The header 62 is of a cup-like shape and has its rim portion 63 secured within the depression of plate 23 which is formed by the shoulder 55. The cup-like header 32 is provided with a second connecting plug member 65 (see Fig. 4) which is hollowed out as at 66 and has a plurality of apertured baffles 31 alternately disposed relative to one another within this hollowed out part thereof. The sections II are in reality combined refrigerant evaporating and heat exchange units since the elements 56, 51, 6|, 62 and 65 form a means for causing the exchange of heat between liquid refrigerant entering these sections and refrigerant leaving same.

After the members 3| are. unidirectionally nested together and other parts of section or unit II are assembled to one another in the manner described, the troughs 26 are placed upon the unit Each trough 23 comprises a strip of metal 1| which has a leg portion 12 fitted and secured within a slot provided in the members 3|. A curved inwardly part 13 of strip 1| forms the trough portion of the trough 26, and this trough portion extends from one end to the other end of unit along the bottom corners of members 3|. It is to be noted that the sheet metal members 3| have their corners cut off as at 14 and also have their bottom edge out at an angle as at 15 so as to slope this edge from a point centrally of the members to the cut-oi! corners 14. This contour of the edge portions of members 3| provides for the flow of moisture from members 3| to the point of juncture between the cuts I4 and 15 in the members. In

The bottom wall 35 of the cup porother words moisture, taken up by the cooling effect produced by the evaporator l3, flowing from walls of refrigerant passage 34 and from members 3| is directed, by the angled edges 14 and I5, to a point directly above troughs 26 from which point the moisture drips into the troughs and is conveyed out of the compartment being cooled to a drain. The telescoping and securing together of the unidirectionally superimposed or nested passage-forming portions 33 of members 3| and the brazing of the liquid refrigerant conveying pipe 4| to the ears 36 and web portions 33 of the wall 35 of members 3| materially increases the structural strength of the sections or units ll of the evaporator. The ears 36, being spaced apart along the length of pipe 4| closes portions of the narrow slot 44 in pipe 4|, to thereby provide the pipe with a plurality of spaced apart outlets for distributing incoming liquid refrigerant to a plurality of points along the length of the passage 34. It is to be understood that the various parts of the section or unit II are secured together after assembly thereof to one another by brazing or soldering in any conventional or desirable manner well known to those skilled in the art. In building up a plurality of sections or units II in the manner described, it will be apparent that any desired size evaporator or cooling element may be provided. Thus, manufacturing costs are reduced by the present invention since substantially identical units II are provided to be assembled and secured together to provide an evaporator comprising any desired number of banks or rows of refrigerant evaporating sections. NLv invention eliminates the carrying in stock of a plurality of evaporators of different size to thereby save floor storage space while, at the same time, permitting evaporators of any desired over-all dimensions to be constructed.

Referring now to Fig. 5 of the drawings, it will be noted that I have shown an evaporator or cooling element Ilia which resembles the evaporator |3 but comprises sections or units ||a of a modified construction. These sections or units Ila of evaporator Ilia include metal members 3| having a fin portion 32 and a cup or tubeforming portion 33. These members 3| are superimposed upon one another with their portion 33 telescoped and secured together to form a refrigerant evaporating passage 34 within the unit Ila. The end wall 35 of the cup or tube portion 33 of members 3| is perforated as at 33 to provide ears 31. The end wall 35 also has an opening cut in the central part thereof for receiving a liquid refrigerant distributing pipe 33. End wall 35 of members 3| is further perforated as at 33 to form a plurality of holes disposed below the plane of pipe 33 for permitting free circulation of refrigerant within the refrigerant passage 34. The pipe 33 is closed at its one end by a plug 3| which has a small orifice 32 provided therein. Pipe 33 also has a plurality of horizontally spaced apart openings 33 provided therein. The end of pipe 33 opposite the plug end 3| is tapered as at 34 to receive similarly tapered portions provided on a plurality of fin members 35 which are telescoped and secured together. Members 35 have a wall surface 36 at the end of thetaperedportionsthereof which is apertured as at 31 to form a substantially restricted passage or conduit leading to pipe 33. The telescoped together fln members 35 are located within a. header |3|, secured to an end plate I32, which header is provided with outlet pipe connections I03, I and I00 (see Figs. and 9) and inlet. pipe connections I06, I01 and I 00. The fin members 95 "located, within headers IOI provide the sections or units Ila with a heat exchanger, the purpose of which will be hereinafter more fully described. When the headers are connected in a refrigerating system, as shown in Fig. 5 of the drawings, the refrigerant outlet connection I05 of header IOI is closed by a plug I09 (see Figs. 5 and 9) and the refrigerant inlet connection I08 is closed by a plug III. The extra plugged refrigerant connections I09 and III to headers IOI described provides for a plurality of different pipe connecting arrangements of the evaporators l0 and I0a in a refrigeratlngsystem. For example, the evaporator l0a is connected in a refrigerating system in a manner similar to the connection of evaporator I0. However, if desired, the gaseous refrigerant return pipe I8a may be connected directly to each individual header I0l of evaporator l0a by plugging the outlet connections I03 and I04 of the headers and utilizing the outlet I05 only for withdrawing gaseous refrigerant from the sections or units Ho. The inlet connections I06 and I01 may also be plugged and the central inlet I08 employed'to direct liquid refrigerant to a section Ila. In this manner the sections or units Ila are rendered substantially universal in use and need not be of different design should dif- 'ferent hookups be required in various installations.

In Fig. '1 of the drawings I have disclosed a slightly modified construction of a section or unit of an evaporator. In this showing of the invention a section or unit Ilb of an evaporator is composed of a? plurality of punched sheet metal members I2 I which have one of their side portions cut off as at I22. The members III are all of identical form or contour and are superimposed in alternate relation upon one another so that the fin portion I23 of one member III is disposed opposite the similar fin portion of another member I2I. Aside from this difference the members I2I are punched and formed to correspond with the structure of the metal members 0| of section Ila. Thus, the modified showing in Fig. 7 provides refrigerant evaporating sections or units which, for certain or desired reasons, do not" possess quite as much fin surface as the sections or units II or Ila.

Having described the various structures disclosed, I now wish to explain the manner in which refrigerant is circulated into and out of the sections of the improved evaporators. Liquid refrigerant fiows from the feed pipe I Ii through branch;pipes I 5 (see Fig. 1) to connec tions I 2 and from these connections I! through connecting members 6| and conduit into the liquid refrigerant distributing pipe I4. Since every section Ill'of evaporator I0 is provided with a connection I2 and connecting members 8|, these sections each receive a supply of liquid refrigerant from the feed pipe I8. The slot 44 in pipe ll is open between the cars 36, and these openings distribute the incoming liquid refrigerant at a plurality of points along the length of passage 34. The refrigerant, upon absorbing heat and evaporating within passage 04, flows to the header 62. The cool evaporated refrigerant contacting and flowing around the fins 51 and conduit 58 cools the liquid refrigerant flowing through this conduit 56 from connector 6| to p I. The gaseous refrigerant in header 62 passes around the names 61 and through connector 65 to pipe I1 from where it is withdrawn from the sections II of evaporator I0 through pipe I8. In the embodiment of the invention shown in Figs. 5 and 6, the liquid refrigerant is directed to passage 84 through the holes or orifices 92 and 83, and the cool expanded refrigerant flows around the finned passage or conduit 91 to remove heat from the relatively warm incoming liquid refrigerant.

From the foregoing, it will be seen that I have provided an improved unitary evaporator or cooling element for a refrigerating system which can be made of any desired size by employing a predetermined number of similar sections constructed from a plurality of unidirectionally nested and secured together integral fin and tube members. My improved structure not only provides for the maximum heat transfer from a fluid to be cooled to refrigerant in the evaporator but also provides for the exchange of heat between the relatively warm liquid refrigerant flowing into the plurality of sections of the evaporator and cool expanded refrigerant leaving the sections of the evaporator. By providing each section of my evaporator with a heat exchanger of the type described, the evaporator is rendered more eflicient and the various sections thereof are maintained at substantially the same temperature to thereby reduce the temperature gradiant between portions of the evaporator. My improved evaporator construction reduces manufacturing costs and also permits the construction of eyaporators of different sizes relative to one another from a plurality of similar sections which are secured together.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. An individual section having a single closed refrigerant evaporating passage therein for a sectional cooling element of a refrigerating system comprising, a plurality of fin members each having a tube portion extending therefrom, said fin members being superimposed one upon the other with the tube portion of one member telescoped with and secured to the tube portion of another member to provide said closed refrigerant evaporating passage which extends through the section, means secured to one end of said section and forming a part of saidsingle closed refrigerant evaporating passage therein, said means being provided with a liquid refrigerant inlet connection and a refrigerant outlet connection, a conduit within said means extending from said inlet connection thereof into said refrigerant evaporating passage for directing liquid refrigerant entering said section to a point in said passage remote from said inlet connection, a portion of said conduit being disposed in the path of refrigerant flowing from said passage through said outlet connection and forming a heat exchanger within said section between refrigerant entering and refrigerant leaving same, and said conduit portion having fin means thereon for increasing the heat transfer surface of said heat exchanger.

2. An individual section having a single closed refrigerant evaporating passage therein for a sectional cooling element of a refrigerating system comprising, a plurality of fin members each having a tube portion extending therefrom, said fin members being superimposed one upon the other with the tube portion of one member telescoped with and secured to the tube portion of another member to provide said closed refrigerant evaporating passage which extends through the section, means secured to one end of said section and forming a part of said single closed refrigerant evaporating passage therein, said means being provided with a liquid refrigerant inlet connection and a refrigerant outlet connection. a conduit wtihin said means extending from said inlet connection thereof into said refrigerant evaporating passage for directing liquid refrigerant entering said section to a point in said passage remote from said inlet connection, a portion of said conduit being disposed in the path of refrigerant flowing from said passage through said outlet connection and forming a heat exchanger within said section between refrigerant entering and refrigerant leaving same. and said portion of said conduit including a plurality of fin members each having a tubular part extending therefrom telescoped and secured together to form the walls of said conduit portion.

3. An individual section having a single closed refrigerant evaporating passage therein for a sectional cooling element of a refrigerating system comprising, means forming walls of said single closed refrigerant evaporating passage, means secured to said first named means at one end of said section and forming part of said refrigerant passage, said last named means being provided with a liquid refrigerant inlet connection and a refrigerant outlet connection, a conduit within said last named means extending from said inlet connection thereof into said passage for directing liquid refrigerant entering said section to a point in said passage remote from said inlet connection, .a portion of said conduit being disposed in the path of refrigerant flowing from said passage through said outlet connection and forming a heat exchanger within said section between refrigerant entering and refrigerant leaving same, and said conduit portion having fin means thereon for increasing the heat transfer surface of said heat exchanger.

4. An individual section having a single closed refrigerant evaporating passage therein for a sectional cooling element of a refrigerating systern comprising, means forming walls of said single closed refrigerant evaporating passage, means secured to said first named means atone end of said section and forming part of said refrigerant passage, said last named means being provided with a liquid refrigerant inlet connection and a refrigerant outlet connection, a conduit within said last named means extending from said inlet connection thereof into said passage for directiing liquid refrgerant entering said secton to a point in said passage remote from said inlet connection, a portion of said conduit being disposed in the path of refrigerant flowing from said passage through said outlet connection and forming a heat exchanger within said section between refrigerant entering and refrigerant leaving same, and said portion of said conduit including a plurality of fin members each having a tubular part extending therefrom telescoped and secured together to form the walls of said conduit portion.

JOHN KARMAZIN. 

